PITTSBURGH — The Senators’ Game 1 win over the Penguins came with a huge cost.

After the Senators wrapped up their 35-minute practice Thursday at Mellon Arena, GM Bryan Murray announced winger Milan Michalek will be out until next September after tearing the ACL in his left knee Wednesday.

Michalek suffered a partially torn ACL March 18 in Atlanta and missed nine games. He put on a brace and worked hard to delay surgery until the off-season. This time, the blow was so strong, surgery is unavoidable.

It’s the second time in a week the Senators have lost one of their scoring forwards with a torn ACL, taking a total of 40 goals out of the lineup. Winger Alexei Kovalev suffered a similar injury last Thursday against the Tampa Bay Lightning.

“It’s the tough news of the day from our point of view,” said Murray. “When you go into the playoffs and you have some key people hurt, it makes it more difficult. The fortunate part is we have a few young people that have really made some nice strides over the course of time.

“We still have our key people playing and playing fairly well at this point. We just have to count on the group playing real hard together to get goals wherever they can through effort.”

Michalek, 23, who had 22 goals and 12 assists in 66 games this season, had, at his own request, been moved to the right side of Mike Fisher and Matt Cullen. Nick Foligno skated there Thursday.

Winger Ryan Shannon will return to the lineup Friday.

“This is playoff hockey and this is my opportunity to play solid minutes and contribute to the team,” said Shannon.

The Senators aren’t going to let the injury become an excuse. Somebody will pick up Michalek’s minutes. Coach Cory Clouston noted Ottawa went through long stretches without Michalek during the regular season.

“I guess the only plus side is we have played a lot of games without him,” said Clouston. “He’s had some injuries throughout the season and we’ve been able to adjust. It’s tough to replace a player like him, but we’ve had to do it in the past and we’ll do it again.”

Centre Jason Spezza, who had his own bouts with injuries at mid-season, said the Senators have had to deal with adversity all year and this is just another challenge.

“With the way the schedule has been, we’ve played shorthanded all year,” said Spezza. “I think we had a healthy lineup once in October and once in April. Unfortunately we’re a little used to playing short-handed, but different guys have stepped up and played different roles.”

Captain Daniel Alfredsson said the Senators have plenty of confidence.

“I don’t see this as a big problem for us,” Alfredsson said. “You would love to stay healthy, but we’re not. We’re not going to change anything. Everybody is going to pull as hard as they can, no matter what happens.

“We’ve played a system throughout the year that everybody is comfortable with and it shouldn’t be a problem for whoever gets the chance to go in and play well.”